1. Field of the Invention
The present invention relates generally to a method and apparatus for surgically closing an open abdomen of a patient, and more particularly to a method and apparatus for surgically closing acute and chronic open abdomen wounds.
2. Description of the Related Art
A variety of different medical conditions or accidental injuries can result in a patient having an open abdomen wound. For instance, in some medical conditions, the viscera within the abdomen swells which causes the viscera to be compressed by the abdominal wall of the person. Unless decompressed, the compression results in loss of circulation to the viscera and to tissue death, which may result in death of the patient. The pressure within the abdomen can be relieved by surgical opening of the abdomen, such as by a ventral incision, as a prophylactic procedure. While the risk of death and visceral tissue loss is decreased by the decompression while the tissues heal, the abdominal incision must be closed after the swelling decreases. The muscles of the abdominal wall, however, generally retract while the incision is open, pulling the wound open and preventing the wound from being closed. This is referred to as lost domain, and the result is a patient with an open abdominal wound, referred to as the complex open abdomen.
Injuries to the viscera such as from a gunshot or knife wound, vehicular accident or other injury can also cause swelling of the viscera, particularly where a surgical repair of the bowels, intestines and other organs are required. The act of operating on the abdominal tissues may also cause the tissues to swell or otherwise change in a way that causes issues in attempting to close the wound. At the conclusion of the surgery to repair the injury, the swelling as well as any muscle retraction prevents closure of wound in the abdominal wall. As a result, an open abdomen can result that is not immediately able to be surgically closed without risk to the patient. This is referred to as an acute open abdomen.
Contemporary surgeons struggle with the complex open abdomen. In years past, it was rare to have a persistently open abdomen. In contrast, for a number of reasons, contemporary practitioners routinely leave abdomens open after ceilotomy. Complex open abdomens are often the result of damage control laparotomy for trauma, decompression for abdominal compartment syndrome, and massive, possibly excessive, fluid resuscitations resulting in bowel and abdominal wall edema. It is estimated that up to one in nine patients undergoing laparotomy for trauma is not closed at the time of initial surgery.
In some patients who have had need for an open abdomen, the open wound has been closed by a skin graft, thus essentially forming a large ventral hernia on the abdomen. This is referred to as a chronic open abdomen. While the skin graft encloses the viscera within the skin, it does not provide the protection for the viscera that the muscles and other structures of the abdominal wall provide. The patient no longer has integrity of the abdominal wall, which may limit many of the activities that the patient may wish to engage in. In addition, the rectus muscles, those which allow one to flex the abdomen in doing a “sit up” type maneuver, end up very lateral and no longer attached to one another. By being so lateral and not bound to each other, the individual is unable to flex the torso, thus being functionally impaired.
Several options exist for the management of the increasingly common open abdomen wound. However, due to idiosyncratic complexities associated with this group of patients as well as institutional variability, no single technique can be universally employed to manage these cases. Current techniques include planned ventral hernia with placement of absorbable mesh and/or skin graft as noted above, vacuum assisted closure, complex abdominal wall repairs, and a variety of temporary closures with serial attempts at tightening. The complex repairs include component separation, in other words, separation of the muscles and other tissues in the abdominal wall from one another and connecting just some components together. Among the serial tightening techniques is the Wittmann Patch, which is an artificial bur which serves as a temporary abdominal fascial prosthesis in cases where the abdomen cannot be closed due to abdominal compartment syndrome or because multiple further operations are planned (staged abdominal repair). It consists of a sterile hook and a sterile loop sheet made from propylene or other polymer.
In particular, the Wittmann patch includes two sheets of a biocompatible polymer; one sheet is covered with micro hooks or mushrooms and the other with loops. These sheets have been traditionally sutured to the fascial edges of an open abdomen and then pressed together to adhere. When adhered to each other, these sheets can withstand shear forces similar to normal intact fascia. The patch sheets are sequentially trimmed and progressively pulled tighter across the open abdomen to slowly stretch the abdominal wall, regain domain and eventually re-approximate the fascia, or close the open wound.
In recent years, several doctors have reported improved success by combining the Wittmann Patch with vacuum assisted dressings. Doctors report following the same method of implanting the patch by sewing it directly to the fascial edge. Fixing the patch to the leading edge of the fascia places substantial force on a focused area of tissue. As a result, complications of fascial necrosis and tearing where the patch interfaces with the fascial edge are often reported. This loss of fascial integrity is sometimes of sufficient extent to cause patch failure. The tissues won't hold the suture. In an attempt to prevent tissue damage, less tension forces are applied to the patch so that it won't tear through the fascial wall where it has been sewn. More importantly, this method of Wittmann Patch fixation often sacrifices several centimeters of precious abdominal wall which could be used to restore abdominal integrity. The result may be a hernia rather than a successful closure of the abdominal wall structures.
The health of the patient plays a roll in the ability to close an open abdomen. For example, patients with a condition such as diabetes may have poor tissue quality at the abdominal wall anyway. Efforts to close the open abdomen can result in further tissue degradation.
Another approach has been to provide elastomeric bands that span the open wound. The elastomeric bands apply a dynamic tension to the tissues by exerting a dynamic pull on the muscles and other tissues.